Pension Plan (Tables)

12 Months Ended

Dec. 31, 2019

Retirement Benefits [Abstract]

Schedule of pension plans and their reconciliation

	December 31, 2019			September 30, 2018
	(in millions)
Change in benefit obligation:
Benefit obligation at beginning of period	$	94.1		$	105.9
Interest cost		2.7			2.9
Prior service cost		—			0.5
Actuarial (gain)/loss		14.1			(8.3	)
Benefits paid		(4.2	)		(2.6	)
Foreign currency translation adjustments		3.7			(2.6	)
Benefit obligation at end of period	$	110.4		$	95.8
Change in plan assets:
Fair value of plan assets at beginning of period	$	97.4		$	102.5
Actual gain/(loss) on plan assets		10.3			0.7
Employer contributions		0.2			3.3
Benefits paid		(4.2	)		(2.6	)
Foreign currency translation adjustments		3.6			(2.8	)
Fair value of assets at end of period	$	107.3		$	101.1
Amount recognized in the consolidated balance sheets:
Overfunded (Unfunded) status (non-current)	$	(3.1	)	$	5.3
Net amount recognized	$	(3.1	)	$	5.3

Schedule of defined benefit plans

	December 31, 2019			September 30, 2018
	(in millions)
Components of net periodic pension benefit cost:
Interest cost	$	2.7		$	3.0
Expected return on plan assets		(3.5	)		(3.7	)
Amortization of net loss		0.3			0.4
Net periodic (benefit) cost	$	(0.5	)	$	(0.3	)

Schedule of fair value of the plan assets

	Level 1		Level 2		Level 3		Total
	(in millions)
Diversified fund	$	—	$	68.0	$	—	$	68.0
Buy-in contract		—		—		38.8		38.8
Cash		0.5		—		—		0.5
Total	$	0.5	$	68.0	$	38.8	$	107.3

	Level 1		Level 2		Level 3		Total
	(in millions)
Diversified fund	$	—	$	63.9	$	—	$	63.9
Buy-in contract		—		—		36.6		36.6
Cash		0.6		—		—		0.6
Total	$	0.6	$	63.9	$	36.6	$	101.1

Schedule of benefit obligation and net periodic benefit cost for the Plan

	December 31, 2019			September 30, 2018
Discount rate		2.10	%		2.90	%
Expected return on assets		3.00	%		3.70	%
RPI inflation		3.00	%		3.20	%
CPI inflation		2.10	%		2.20	%
Pension increases – pre-2006 service		2.90	%		3.10	%
Pension increases – post-2006 service		2.10	%		2.20	%

Schedule of benefit payments are expected to be paid

	(in millions)
2020	$	2.7
2021	$	2.8
2022	$	2.9
2023	$	3.1
2023	$	3.1
Thereafter	$	19.3